1. Field of the Invention
The present invention relates to additive manufacturing and automation systems and techniques, such as three dimensional fabrication.
2. Background
There have been many developments in additive manufacturing in recent years, and three dimensional fabrication or “printing” systems have become an increasingly practical means of manufacturing organic and inorganic materials from a digital model. For clarity, three dimensional fabricators may be referred to as an additive manufacturing device or 3D Printer. A description of many such fabrication systems and recent developments in the art can be found in U.S. Pat. No. 7,625,198 to Lipson et al. and the patents and publications referenced therein.
Currently, many additive manufacturing devices employ a filament based system in which the device extrudes a pre-made, mono-color (often plastic) filament through a constrained, heated deposition head. Devices of this nature use large, mass produced spools or “cartridges” (i.e. small, enclosed spools) of plastic filament. Such spools tend to become tangled and make existing additive manufacturing systems clumsy and predisposed to undesirable results. Such systems practically limit the additive manufacturing devices to single color/material output products. By extruding the filament through a “static” deposition head, the shape and size of the liquefied material is constrained. The same problem occurs in additive manufacturing devices which do not use solid filaments, but instead fluid lines. Therefore, upon manufacturing an output product with a flat surface, the deposition head must make several passes and deposit several “paths” of the same size/shape. This process leads to output products which are clearly identified to have been created by additive manufacturing, due to the zigzagged appearance of flat surfaces resulting from having a single, static deposition lumen shape/size, which must be passed over a flat surface in several paths.
Due to the inherent complexities of additive manufacturing and the shortcomings in currently known techniques, existing additive manufacturing systems may fail to achieve optimal levels of performance and product quality. Current systems are generally limited to mono-material and mono-color prints and cannot adapt well to a user's desired material properties and physical appearance. In particular, it would be desirable to have additive manufacturing systems and techniques that do not result in output products that have noticeable imperfections or are otherwise inferior to products from non-additive manufacturing systems and techniques.